Screen for hammer mill grinders



Patented Sept. 15, 1936 UNITED STATES PATENT OFFICE 1 Claim.

It is a known fact that in grinding machines of the hammer mill type, the material under treatment will, when the material is tough and fibrous, build up on the screen choking the screen 5 and retarding the operation of the hammers. to the end that the material passing through the screen is of an inferior grade.

It is therefore the primary object of the present invention, to provide a screen for use in connection with hammer mill grinders which will prevent the building up of the material on the screen, insuring a uniform grinding and. eliminating the material being delivered through the screen in a balled up mass.

Another object of the invention is to provide means for reducing friction and wear on the hammers of the hammer mill, to a minimum to the end that the energy required for operating the hammers will be greatly reduced.

With the foregoing and other objects in view, which will appear as the description proceeds, the invention resides in the combination and arrangement of parts and in the details of construction hereinafter described and claimed, it

being understood that changes in the precise embodiment of the invention herein disclosed, may be made within the scope of what is claimed, without departing from the spirit of the invention.

Referring to the drawing:

Figure 1 is a vertical sectional view through a hammer mill screen, constructed in accordance with the invention.

Figure 2 is a bottom plan view of the screen.

Referring to the drawing in detail, the reference character 5 designates a housing or support for the screen, which is indicated generally by the reference character 6.

The screen includes a body portion in the form of a. curved plate, the curved plate being formed with a cut away portion defining an opening of a length and width slightly less than the length and width of the plate or body portion.

The upper ends of the plate or body portion, are extended laterally at l and provide means whereby the body portion may be secured to the housing or support 5.

The screen also comprises spaced rods 8 that have their ends secured to the body portion 6, the rods extending across the opening of the body portion. Each of these rods provides a support for a roller or sleeve 9, which rotates around 5 the rods to dislodge material which has a tendency to clog the screen.

Extending through the machine, is a shaft In which provides a support for the hammers II that are pivotally supported on the members l2, 10 that in turn are keyed to the shaft ID as clearly shown by Figure 1 of the drawing.

These hammers are of the usual and. wellknown structure, and operate, under normal conditions, in spaced relation with the rollers or 15 sleeves 9, but when tough or fibrous material is being screened, it often happens that the material will build up between the rollers and the hammers, with the result that the material will be delivered through the screen, in a balled up mass, go resulting in an inferior grade of material being screened.

Owing to the construction of applicant's screen, it is obvious that when material builds up on the screen, to such an extent that it is engaged by 25 the rotary hammers H, the rollers or sleeves will move causing the material to drop through the screen, and eliminating any possibility of the material being fed through the machine in a balled up mass. 30

Having thus described the invention, what is claimed is:

A hammer mill grinder screen, comprising a support, a curved plate mounted within the support, said plate having a central cut away por- 35 tion, spaced rods rigidly secured to the outer surface of the curved plate, sleeves rotatably mounted on the rods, the ends of the sleeves engaging the edges of the cut away portion, portions of the sleeves extending only slightly above 40 the inner surface of the plate, and rotary hammers operating above the sleeves and adapted to engage material supported on the sleeves, forcing the material between adjacent sleeves.

HENRY JOHN MANKOIEF. 

